Hydraulic well packer

ABSTRACT

A hydraulic packing device for wellbores, known in the art as “packer”, which is a retrievable device and is used in downhole operations, that is also part of the tools used in wellbore operations, such as oil, water or gas wells, or wells of similar fluids is provided. More specifically, the main object of the invention is a double-latch packer with hydraulic fastening and packing pressure function, double retreat integrated assembly, with elements of rubber packing, which has the advantage of being able to work selectively on facilities with one packer or multiple packers, with the advantage of fastening or releasing the packer selectively in oil, water or gas wells, or wells of similar fluids.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention refers to a hydraulic packing device for wellbores, known in the art as “packer”, which is a retrievable device and is used in downhole operations, that is also part of the tools used in wellbore operations, such as oil, water or gas wells, or wells of similar fluids. More specifically, the main object of the invention is a double-latch packer with hydraulic fastening and packing pressure function, double retreat integrated assembly, with elements of rubber packing, which has the advantage of being able to work selectively on facilities with one packer or multiple packers, with the advantage of fastening or releasing the packer selectively in oil, water or gas wells, or wells of similar fluids.

2. Description of the Prior Art

Within the field of the prior art, several packers are known, which are currently used as retrievable packing tools in oil, water or gas wells, or wells of a similar fluid, where it is necessary to isolate areas in order to carry out production or injection works.

Some of those packers known by the art, so far have the great disadvantage that, when releasing the installation formed by more than one of these packers, they need expansion joints in order not to add individual release efforts; generally they are packers of stress release.

Other devices of this type use rotation releases, which, in the case of installations of more than one packer, make it impossible to rotate de string due to the simultaneous addition of all the release rotation assemblies of each of them, generating an excessive torque when doing it.

As an example, we can cite double latch hydraulic packers that present a number of inconveniences or limitations, such as the following:

In the first place, we could mention the fastening hydraulic packer, whose release assembly is carried out by the string rotation and, as a consequence, by the mandrel of the packer. This kind of model presents the limitation of having to generate several spins to unpack the rubbers and finally disengage the clamps. In wells with degrees of inclination or where, as part of the installation, there are intermediate injection devices, it is very difficult to generate the necessary spins in order to obtain the release of the tool, due to the generation of high torques in the maneuver string, which makes it impossible. Moreover, it goes without saying that it would be even more difficult if the installation had more than one packer with this release assembly, because there would be an addition of the rotation efforts of each of the packers.

Secondly, we could mention the hydraulic fastening and stress release packer. This kind of model has the feature that, in order to release the tool once it has been fastened, traction must be applied over the mandrel to cut the safety assembly and to release the packer completely. If there are installations with several packers, the forces on each of them to release are joined, since packers help each other through the mandrels. The production strings have a limitation in the corresponding traction that is solved with this type of installations. In other words, it is necessary to have some kind of intermediate supplementary device to compensate the forces of each packer and not to transmit it downward to the other packer. Another limitation to bear in mind is that in some of these packer models, the mechanical works of the tubing between packers derived from the pressure changes might generate stress or cuts in the safety mechanisms, which causes an early release of the tools.

SUMMARY OF THE INVENTION

Therefore the object of the present invention is to provide a double grip packer with hydraulic fastening and packing pressure capable of solving the inconveniences mentioned earlier, being a packer that offers an original result, which includes a bigger fastening confidence, simplicity in the release operation, which is highly recommendable in the use of the selective installations of multiple packer, with the advantage of being able to fasten or release the packers selectively without letting the production or maneuver string suffer traction efforts or excessive rotation.

In comparison with the packers mentioned, the packer of the present invention presents several outstanding features that allow fulfilling the needs and coping with the deficiencies of the existing packers for this type of applications that the market offers. The present packer includes mainly the split mandrel, base of this invention, that has a mandrel or upper part, and a mandrel or lower part, connected through a threaded connection, an upper anchoring assembly that, once the packer is released, allows the upper mandrel of the packer to help its intermediate peripheral portion, a corrugated assembly that allows the lower mandrel and its intermediate peripheral portion to help each other, and from there downward to the rest of the installation, an anchoring assembly that, when releasing the packer, prevents it from being packed again. All this assembly, once the packer is released, manages to make this act as if it all was a rigid assembly and allows it to transmit stress, weight or torque, in an independent fashion downward, without consuming efforts to release another packer or other part of the installation, or to simply retrieve it and take it out of the well. It also has a hydraulic fastening pressure assembly, which activates a hydraulic chamber that starts its course cutting shear pins and comprising the package of elements or packing rubbers, which can be added or taken out depending on the state of the well or the work to be carried out; this compression of packing elements is sustained by safety assembly that prevents its unpacking once the hydraulic pressure has been released; at the same time, the packing package exerts a force on the upper cone that fastens the gripping means of both directions created by double latch clamps that can be set up as comprehensive or individual clamps, depending of the configuration of the wells and the forces to support; at the same time, these clamps can have treated latch teeth or hard metal inserts.

As described, one of the most important virtues of this packer model is that the release is achieved with less than one spin of the maneuver or production string, without transmitting torque at the lower part of the packer, when releasing the packer, due to the fact that the split mandrel is connected with a quick thread. Once this thread is disengaged, the upper mandrel is raised and the packing assembly contained is released; the string keeps being raised while the clamps are released. Then the upper mandrel is connected to the periphery of the packer, through the tower, and this periphery with the lower mandrel of the packer, through the spire. In this way, the packer is absolutely free in terms of the tightness of the packing elements, in the shape of rubbers, over the well casing, and in terms of the casing latch, allowing it to release another packer under itself or under part of the installation, as in this state it will transmit, stress, torque or weight as a solid whole.

Another great advantage is that, due to the geometry of the mechanism, it allows larger interior diameters in the junctions of the mandrel, which are very useful in the use of this type of packer for the selective installations, as it is very common to pass tools of smaller diameter through the mandrel of the packer.

Comparing the packer of the invention with the other two retrievable packer variants already mentioned the advantages that the invention offers are:

In relation with the making mentioned earlier, the packer of the present invention presents the advantage that, at the moment of the release, a rotation of the upper mandrel can be carried out of less than one independent spin of the lower part, without transmitting torque at that moment towards the lower part of the tool and, as a result, towards the rest of the installation. This is so because the present packer has a split mandrel that, at the moment of the release, allows it to apply only the torque necessary to release this quick thread, and with this, to easily start with the release of the packer, without transmitting that torque downward. After this thread is released, the tubing is raised and the packing elements loose compression. As a result of that upward movement, the clamps are released, and at the same time the upper mandrel is inserted in the tower, allowing the periphery of the packer to help the upper mandrel, and this one to help the lower one; therefore, with just a small torque of less than one spin and an upward movement, not only the packer in question is released, but it is also ready to act as a rigid assembly to exert rotation movements of weight and traction in order to keep moving the string, with the aim of releasing the other lower packer and other tools of the installation.

In relation with the making mentioned secondly, the packer of the present invention presents the essential advantage that it does not require stress to be released, it only needs a small rotation of less than one spin, and therefore, in its anchoring assembly and tightness it is not tied to bolt cutting assemblies that may be cut easily due to the tubing pressure in the mechanical work, but mainly that the released assemblies by stress need to stress the spring and if the installation has more than one packer of these features, the efforts to cut the release bolts are to one another, making an assembly like this very difficult to release, as the sum of all the cutting forces of each packer exceeds the traction mechanical capacity of the tubing. Note that there are wells with considerable deflections, where the stress forces—due to the pulling of the tubing in the casing—limit the capacity to maneuver with stress these installations. Completing this explanation, we can mention that the packer of the present invention is independent of the mechanical works that the tubing might have due to the pressure changes, as its double latch fastening assembly is independent of any other type of movement. Once the casing is fastened, the weight or stress can be applied to it, without any limitation needed for its operation and without affecting its functioning. We know that when there are increases in the pressure within the tubing located between two packers that help the casing of the well, the tubing experiences a swelling that produces a stress increase on its ends, that is, it tends to shorten, therefore in the packer technology with stress release it can generate a release that is carried out before the required one.

In many aspects, the present packer is a tool that presents many advantages: It comprises mainly a mandrel with an upper part and a lower part axially connected to each other through a quick sealed thread fastened with a shear pin calibrated for torque, therefore, it supports internal and external pressure, traction and weight. The direction of the thread can be configured from right to left according to the features of the installation to be lowered or according to the well.

It has a safety pin assembly configurable to prevent the accidental fastening of the tool, which allows to select both the amount of pins and materials in order to establish the exact pressure needed to start with the fastening.

The packer of the invention has an upper insert assembly that, once the tool has been released, allows the portion of the upper mandrel of the packer to help the intermediate peripheral portion of the tool. This assembly is formed by an insert known as tower, being one part located in the lower portion of the segment carrying sleeve, and the other, in the part located in lower part of the upper mandrel. It is a notched assembly that, when the teeth of the upper and lower parts touch each other and couple, allows the torque to be transmitted from the upper part of the packer towards the intermediate part, that is, to the parts that can help the others. It also has a corrugated assembly located in the lower mandrel and the joint sleeve, connecting in terms of torque the intermediate peripheral portion with the lower mandrel, allowing also in this way to transmit torque, but allowing the movement of the joint sleeve at the time of the fastening, in order to compress the packing elements. This is why the torque can be transmitted when it is free, from the upper mandrel through the periphery towards the lower mandrel, and from there to the rest of the installation or to whatever there is under the packer. The present packer also has a locking ring assembly that, at the time of releasing the packer, prevents this one from returning to its previous position, that is, to being packed and wedged. This is achieved because at the time of turning and splitting the upper mandrel, the extension assembly is stuck in terms of length, due to the safety bolt, and rigid, in terms of the torque, due to the tower and spire insert assembly. All this assembly, once the packer is released, manages to make this act as if it all were a rigid assembly and allows it to transmit stress, weight or torque, in an independent fashion downward, without consuming efforts to release another packer or other part of the installation, or to simply retrieve it and take it out of the well.

The fastening assembly of the packer of the invention operates with hydraulic pressure. In order to carry out the fastening of the packer, it is necessary to smother the lower mandrel temporarily so as to generate enough hydraulic pressure within the mandrel to start with the injection. The hydraulic pressure activates a hydraulic chamber that begins its route cutting safety pins, moving downward and compressing the package of elements or packing rubbers. This package of packing elements, in turn, compresses an upper cone cutting other security pins and anchoring the clamps of the well casing. The amount and hardness of the packing elements can vary depending on the state of the well or the work to be performed; this compression of packing elements is supported by safety bolt assembly with saw tooth located in the segment carrying sleeve, which prevents its unpacking and assembly restitution, once the hydraulic pressure has been released.

The present invention comprises gripping means in both directions generated by double latch clamps that can be configured as comprehensive or individual clamps, depending of the features of the wells and the forces to support; these clamps in turn can be hardened treated gripping tines or tines with hard metal inserts.

The present packer comprises security stages controlled by calibrated shear pins allowing to configure selectively the necessary pressure to exert the forces in the different parts of the tools; and not only in one tool, because if the packer is a part of the installation of the different packers of the invention, the security assembly of these can be configured in a different way selectively to be able to control, together with the different pressures, which of them needs to be fastened to the casing first and in what stages.

One of the most outstanding virtues of this packer is that the release is achieved with less than one spin in the maneuver or production string. This thread is secured through a shear pin calibrated by torque, which to fracture it requires a certain calculated torque to make the turn begin. The aim of this shear pin is to prevent the packer from being free due to any accidental turn of the maneuver or production string. The direction of the turn can be configured to the right or to the left, depending on the operative needs. For this release, it is necessary to transmit only torque to the upper mandrel and also to disengage the quick thread, because as it has its split mandrel connected only with the quick thread, this is easily achieved. Once this turn is achieved and it disengages the thread that connects the mandrel in two parts, the parts quickly disengage, it is raised and with this the packing assembly contained is released. If there was a pressure difference between the interior and the exterior of the packer, once the thread is released, raising the upper portion of the mandrel makes the balance orifice in line and balances the pressures. After this, the packing assembly is completely unpacked because the tool is balanced.

The packer has a release safety assembly that prevents the packing and the tool latch from being free once it is completely released; this is achieved through a locking ring that prevents the packer mechanism from being packed again and having the clamps of the well casing fastened.

Another essential advantage of this packer is that, once the tool has been released and secured, it acts as a rigid whole that can transmit torque, weight or stress to the rest of the string or installation, or can take it out of the well. This is achieved because when the string is raised and in turn releases the clamps, the upper mandrel is connected to the periphery of the packer through the tower, and this one is connected to the lower part through the spire. In this way, the packer is absolutely free in terms of the tightness in the casing and in terms of the latch on the well casing, allowing it to perform the maneuvers required, such as releasing the packer below it or another part of the installation.

Due to the geometry of the mechanism, the present packer allows larger interior diameters in the joints of the mandrel, which are very useful in the use of this type of packer for the selective installations, as it is very common to pass tools of fewer diameters through the mandrel of the packer.

Therefore, the object of the present invention is to provide a retrievable packer and one that can be used in downhole operations that is part of the tools used in wellbores, specially used for the selective installations, such as oil, water or gas wells, or wells of similar fluids. More specifically, the main object of the invention is to provide a double latch packer with pressure hydraulic fastening and packing, double integrated safety bolt assembly with elements of rubber packing, which presents the advantage of being useful on installations of multiple packers with the purpose of solving the problems that arise from incidental releases and the excessive forces at the time releasing the installations of multiple packers, with the benefit of fastening or releasing the packer selectively.

BRIEF DESCRIPTION OF THE DRAWINGS

For more clarity and comprehension of the object of the present invention, a figure has been drawn, as an example, in which the invention has been represented with the preferred (possible) embodiment, where:

FIGS. 1 a and 1 b show a profile view in vertical semi-cut of the preferred embodiment of the packer of the present invention, as an example.

DETAILED DESCRIPTION OF THE INVENTION

Describing the exemplifying device of the present invention and making reference to the Figure, it can be observed that the retrievable hydraulic packer with double latch comprises a tool to be applied when it is necessary to isolate or seal temporarily or permanently the well area, with the possibility to carry out different operations, specially used on selective installations, such as oil, water or gas wells, or wells of different fluids.

The packer of the present invention comprises, in the upper end, an upper header 1, that may have a male or female thread, where there is a mandrel threaded, which according to the invention, is a split mandrel formed by an upper mandrel 3 and a lower mandrel 17. Mandrel 3 is isolated by seal 2 and over upper mandrel 2 there is a compression safety assembly formed by pin 4 that houses in its periphery a plurality of safety shear pins 4 and the screw 5 that is used to retain and press the shear pins 6 against the notches of the upper mandrel 3. Threaded to pin 4, there is segment carrying sleeve 7 that houses segment 8, segment carrying cone 9 and friction ring 10. In the lower part of segment carrying sleeve 7 there is a plurality of teeth 7A known in the art as battlement-shaped teeth.

Threaded to segment carrying sleeve 7 there is hydraulic sleeve 11, whose upper part houses pressure balance orifice 35.

Upper mandrel 3 has in its lower part a plurality of battlement-shaped teeth 3A and can house O-ring seals 13 and shear pins 15. These shear pins 15 fasten upper mandrel 3 with lower mandrel 17 to prevent that an incidental torque releases the tool that is, they are calibrated with a calculated torque to break them and make the turn to release the tool.

Lower mandrel 17 is threaded through a quick thread to upper mandrel 3 and, in turn, isolated hydraulically through O-ring seal 12 and 14. On its upper part, below O-ring seals 14, there is balance orifice 36 towards hydraulic sleeve 11, where the pressure needed to begin the movement of hydraulic sleeve 11 downward originates.

Threaded to hydraulic sleeve 11, there is joint sleeve 18. On the upper part of joint sleeve 18, seal 16 is housed, which has the function of tightening the thread with hydraulic sleeve 11. On the lower internal part of joint sleeve 18, there is spire 18A. Spire 18A works over spire 17 on lower mandrel 17. This spire assembly allows joint sleeve 18 to freely move vertically along lower mandrel 17, but it transmits torque from one component to another, that is to say, from joint sleeve 18 to lower mandrel 17, thanks to the spire. Over the lower part of the joint sleeve, there are O-ring 19 seals housed that move along lower mandrel 17 at the time of the fastening, therefore forming complete hydraulic chamber 37 internally formed by lower mandrel 17, in the upper position by upper mandrel 3 and in its periphery by hydraulic sleeve 11 and joint sleeve 18.

Threaded outside joint sleeve 18, there is upper gauge ring 21, which can be changed and configured with different diameters according to the internal diameters of the well casing. Threaded on joint sleeve 18, there is rubber carrying case 22, which comprises the packing assembly.

The packing assembly described next works over carrying rubber sleeve. The packing assembly can be configured varying the dimensions and the geometry according to the operational needs and also choosing to change the number of rubbers 23 and spacer rings 24, being able to achieve more tightness safety. In the case of the illustrated embodiment, the packer is configured with an assembly of three rubbers 23 and to spacer rings 24. The configurations of rubbers 23 in terms of hardness, diameters and geometry change depending on the internal diameters of the well tubing.

On the lower part of rubber carrying sleeve 22 there is a buffer on which lower gauge ring 26 is stopped. Threaded to the lower gauge ring 26, there is upper cone 27.

Housed on the lower notch of lower mandrel 17, there is locking ring 25 restrained by pressure between lower mandrel 17 and rubber carrying sleeve 22. This ring has a safety function on which after the packer release and when this is stretched, the lower end of rubber carrying sleeve 22 moves upward to locking ring 25, and this one expands itself to be under pressure, preventing rubber carrying sleeve 22 from descending again. In this way, the packing and anchoring assemblies are secured, which cannot return to the compression state. This allows to handle the tool in the well freely and without running the risk of being stuck or anchored.

The anchoring assembly of the present packer comprises unidirectional latch that can be configured as comprehensive or individual clamps, depending on the configurations of the wells and the forces to support; these clamps in turn can have hardened treated latch tines or with hard metal inserts.

In the case of the illustrated embodiment, it comprises a package of clamps 29 which are contained between upper cone 27, lower cone 34 and clamp carrying sleeve 32. In turn, shear pins 28 are housed on the lower part of the upper cone with the aim of preventing the involuntary movement of the parts of the anchoring assembly and therefore preventing any latch to the well casing that was not intended until the moment of fastening.

Finally, on the lower part of lower mandrel 17, lower cone 34 is threaded, sealed with an O-ring 33 seal housed on lower cone 34. The lower end of lower cone 34 is threaded, the thread can be cut as male or female, according to the installation connection that is below the packer.

Operation of the packer:

Now there is a description of the operation of the packer, object of the present invention.

Let us bear in mind that the packer can be lowered individually if just one packer needs to be installed or if it is a part of a multiple installation of packers. For operation purposes of the fastening and release, we can consider the same operative maneuvers individually.

In order to describe it more clearly, we will divide the assemblies in four parts, the fastening assembly in the upper part of the packer, an hydraulic assembly in the intermediate upper part of the packer, a packing assembly in the intermediate lower part of the packer and finally an anchoring assembly in the lower part of the packer.

Fastening: Once the packer is threaded to the tubing, the deepening operation is carried out until the required area for its operation. With the mandrel of the packer temporarily blinded under it or blinded under the installation. In general, a ball seal is used that allows to fill the maneuver or production tubing from down to up, but when applying pressure, the ball covers the orifice allowing to apply hydraulic pressure previously and configured on surface through shear pins calibrated specifically for that housed on the seat, up to a point in which the ball is expelled together with the seat and the passing of the installation is on its full diameter. In this way, it allows to configure the maximum pressure of the packer fastening or the installation of multiple packers. Then hydraulic pressure is applied to the packer or to the installation through a tubing. As the inside of the packer is blinded, the pressure is imparted through the orifice located in the upper part of the lower mandrel and to the portion of the hydraulic assembly formed by the upper mandrel, the hydraulic sleeve, the joint sleeve and the lower mandrel. This hydraulic pressure generates a hydraulic force that becomes a mechanic force of the assembly. This mechanic force generates a movement to below all the assemblies of the packer (as the upper, mandrel is threaded to the string it does not move). The simultaneous movement begins by cutting the shear pins located on the pin case of the fastening assembly. Once these safety pins are cut, the descent of the fastening assembly begins, which is formed by segment, pin case, segment carrying sleeve, segment carrying cone and the friction ring, where the segment that has a saw tooth thread on its internal diameter slips along the upper mandrel, which also has a saw tooth thread on its external diameter. As the saw tooth cut is very small, its illustration is not very graphic, but it is something easy to understand for a technician. This allows that the movement can be performed from down to up, but not from up to down, thus preventing movement.

The hydraulic assembly helps the fastening, therefore, all the movement that can be achieved hydraulically will be the same as the one running along the fastening assembly. With the movement in process, the packing assembly, formed by rubber carrying sleeve, the rubbers and the spacer rings, the packing process begins. With the upper cone, part of the fastening assembly is subject to the force generated by the packing assembly and it will also start its descent together with all the other assemblies, but before the movement is performed in the anchoring assembly, the force of the upper cone will have to cut the shear pins housed between the upper cone and the clamp carrying sleeve, whose function is to prevent that the packer suffers an unwanted fastening in the input of the packer to the well and its descent within it, only until it is required.

Following the application of the hydraulic pressure of the packer will continue the descents of the assemblies and the rubber compression, increasing the tightness of the casing and the wedging of the clamp of the well casing, until the pressure value breaks the device located at the end of the installation described earlier and the pressure falls. At that moment, the packing assembly that is pressed with the packing force will try to restore itself, due to the memory condition of the packing elements of the rubber, but this is when the fastening assembly starts to work as such locking the assemblies: The anchoring assembly to the well casing, the packing assembly to the well casing and fastening to the lower mandrel. At this instance, we mentioned that the packer is fastened and packed to the well, sealing the tubing by annular portion, but allowing the passing of fluids through its interior and applying hydraulic pressures.

It is worth remembering that the installations of this kind may be formed by just one packer or multiple packers.

Release: In order to achieve the release of the packer, one should start by turning the string to the right (or left according to the configuration), exceeding the configured torque of the calibrated shear pin, which will cut, achieving a spin of less than one round, and at that moment, the upper part of the mandrel will disengage from the lower mandrel. The tubing and the mandrel are raised. After disengaging from the lower mandrel, the packing assembly which was compressed, sealed and isolated to the well casing will unpack. It may be that there was a very high differential pressure over the packing assembly in relation with the lower part of the packing assembly; in that case, the rubbers will remain compacted due to the pressure. In that case, the pressure will be balanced and the rubbers will unpack as we describe as follows. The upper mandrel will continue to be raised during the lifting of the upper mandrel, the safety assembly segment will continue to run along the upper mandrel until the tower of the upper mandrel reaches a limit and is inserted in the segment carrying sleeve of the tower, this is the moment when the upper mandrel helps the exterior of the packer and of the periphery of the packer to the lower mandrel through the spire. Continuing with the rising of the upper mandrel which now is helping the fastening assembly, the hydraulic assembly, the packing assembly and the anchoring assembly, the complete balance between the internal pressures of the mandrel and the one in the exterior of the packer is achieved through the upper orifices of the hydraulic sleeve and the packing assembly unpack completely and the clamps of the anchoring assembly are released due to the vertical movement of the upper cone, the clamps are drawn inside due to the compression of the spring and a fundamental thing is carried out that prevents the packer from being anchored again or being packed even with downward movements. When the assemblies are stretched upwards by the upper mandrel, the rubber carrying sleeve exceeds the locking ring; this one expands downward below the sleeve, preventing it from moving downward again, packing the rubbers and anchoring the clamps. At this moment, when the packer is completely free, being able to transmit torque from the upper mandrel to the below the lower mandrel, weight or stress, acting like a rigid unit.

This is why the packer of the present invention is ideal for releasing another packer that is located below the first one, and in turn this one for releasing another one and so on, without having torque added to each other, which allows performing one selective release operation at a time for each packer located on the installation. 

1. Hydraulic well packer of the retrievable type for downhole operations into a wellbore having a casing, wherein the packer comprises: a packing assembly for sealing against the casing, an anchoring assembly for anchoring the packer against the casing, a mandrel, with the packing assembly and the anchoring assembly being mounted in the mandrel, wherein the mandrel comprises an upper mandrel and a lower mandrel axially connected to each other through a threaded connection, and wherein said packing assembly and said anchoring assembly are axially connected to each other and coaxially arranged around said upper and lower mandrels.
 2. A hydraulic well packer according to claim 1, wherein a hydraulic assembly is comprised of said upper and lower mandrels and said upper and lower mandrels define, together with said packing and anchoring assemblies, an annular gap forming a hydraulic chamber for receiving hydraulic pressure for actuating said packing, hydraulic and anchoring assemblies.
 3. A hydraulic well packer according to claim 2, wherein said threaded connection between said upper and lower mandrels is a quick threaded connection, and wherein said upper and lower mandrels are connected through shear pins.
 4. A hydraulic well packer according to claim 3, wherein said upper mandrel is connected to a fastening assembly through at least one shear pin, wherein the fastening assembly is coaxially arranged around said upper mandrel and axially connected to the packing assembly in a manner that the assemblies are arranged in a way down as follows: fastening assembly, hydraulic assembly, packing assembly and anchoring assembly.
 5. A hydraulic well packer according to claim 4, wherein said fastening assembly comprises a pin carrier having a plurality of shear pins retained against corresponding notches in the upper mandrel, with the pin carrier being connected to a segment carrying sleeve that houses a segment, a segment carrying cone and a friction ring.
 6. A hydraulic well packer according to claim 5, wherein the segment carrying sleeve has a plurality of battlement-shaped teeth cut at a lower portion thereof, and said upper mandrel has a plurality of battlement-shaped teeth cut at a lower portion thereof and spaced apart from, but in front of, said plurality of battlement-shaped teeth of the segment carrying sleeve.
 7. A hydraulic well packer according to claim 6, wherein said segment has a saw tooth that is cut in the interior diameter of the segment, the saw tooth forming a unidirectional latch with said upper mandrel.
 8. A hydraulic well packer according to claim 7, wherein said hydraulic assembly comprises, together with said upper and lower mandrels, a hydraulic sleeve that is threadably connected, at an upper portion thereof, to said segment carrying sleeve, said hydraulic sleeve having, at an upper portion thereof, pressure equalizing orifices, with said hydraulic sleeve being connected, at a lower portion thereof, to a joint sleeve.
 9. A hydraulic well packer according to claim 8, wherein said packing assembly comprises a packing seals-carrying sleeve connected, at an upper part thereof, to said joint sleeve, said lower mandrel including a locking ring housed under compression between the lower mandrel and the packing seals-carrying sleeve and capable of expanding if uncovered by the packing seals-carrying sleeve.
 10. A hydraulic well packer according to claim 9, wherein said anchoring assembly comprises a sleeve housing a plurality of clamp shoes, with each shoe being actuated by an upper cone connected to the packing seals-carrying sleeve through a gauge ring, and a lower cone arranged in a lower portion of the lower mandrel.
 11. A hydraulic well packer according to claim 10, wherein said hydraulic chamber is formed, at an inner side thereof, by the lower mandrel and the upper mandrel, and, at an outer side thereof, by the hydraulic sleeve and the joint sleeve. 